Automatic traction hitch



Feb 229 \l. H. LAMBERT AUTOMATIC TRACTION HITCH Filed Sept. 25, 1922 11/1111 vii/14 2 Sheets-$heet L cessive resistance, the coupling serving 'tions for tractor engines matically releasable couplingyadap Edatented Feb, 22:,

"cannon n. LAMBERT, or XENIA, OHIQ.

AUTOMATIC 'rnacrron m'rcn.

' Application filed September 25,

to draw bar connecand the. like and more particularly to a safety hitch or auto ted to yield in the event that the drawn vehicle or implement meets withanobstruction or exsuch disengagement of My invention relates of the tractor...

The invention contemplates disengagement permit is not wholly disconmotive power.

the parts upon disengagement of the toggle pawl is transmitted through an intermediateconnection to a motive power control member such as a clutch lever-or the like, whereby the tractor or other motive power 18 automatically arrested, such intermediate connection having therein an automatic take up device, which may be released to permit the return of the operated power control'member to normal position, preparatory to backing the tractor, the take up serving to read ust the operative connection preparatory to the next operation, such intermediate connection trol member bein of such character as to permit free and independent operation of the control leveror other member to be operated, at the will of the operator independent of its connection with the safety couplin or hitch.

The 0 ject of the invention is to simplify the structure as well as the means and mode of operation of tractor hitches, whereby they will not only be cheapened in construction, but will be more ellicicnt in use, positive in operation, uniform in action, durable and unlikely to get out of repair.

A further object of the invention is to provide an automatic safety hitch or coupling, which may be reengaged after being broken with minimum effort, and without necessity for accurate positioning or alignment of the tractor and the drawn implement or vehicle for reengagement. This is effected by limiting the withdrawal of the to arrest the progress b a telescopic} draw; bar connection, the parts of which are -relatively movable against ance of a pair. of spring actuate togglepawls, which upon limited independent movement of the draw bar, which, however,

yieldin resist- The relative movement of with the power con 4 is a transverse sectional 192a. Seriai No. 590,403.

draw bar to a predetermined ran e. of movement, leaving it connected at t e limit of such movement, with means for guiding it back to its normal engagedposition.

' A further object of the invention is to provide an improved form of yielding toggle pawls or: looking arms, for the draw A further object of the invention is to provide an: improved formof take up for the intermediate tractor control. connection,

which maybe easily and readily relieved to permit manipulation of the tractor mechamsin and will automatically reengage' or reset itself'upon the reengage'm'ent of-the hitch or coupling, preparatoryto the succeeding"releasingpperation. 3

A further object of theflinvention is to provide means controlconnection with the tractor in such manner as to afford free and independent manipulation of the tractor parts under normal conditions of operation. f

With the above primary and other incidental objects in view as will more fully appear in the specification, the invention consists of the features of construction, the piartsand combinations thereof and the mode of operation or their equivalents as hereinafter described and set forth in the claims.

In the accompanying drawings, wherein is shown the preferred, but obviously not necessarily the only form of embodiment of the invention, Fig. 1 is a side elevation of a portion of a tractor and the beam of a drawn implement such as a plow, interconnected by the automatically releasable coupling or safety matter hereof. Fig. 2 is a top plan view of the coupler with the parts in their engaged or operated position, the top or lid of the coupler housing being removed. Fig. 3 is a similar View of the coupler with the parts in disconnected or operated relation. Fig. view substantially on line H of Fig. 2. Fig. 5 discloses a top and side elevation, the latter being partly in section of the jointed locking arm or toggle pawl. Fig. 6 is a side elevation of the automatic take up device and yielding connection, by which movement is transmitted to the tractor control mechanism, to arrest the tractor upon disengagement of for attaching the intervening hitch forming the subject the coupler. Fig. 7 is a detail sectional view on line 7-T of Fig.1. ti. Figs. 8 and 9 are similar views of modifications.

Like parts are indicated by similar characters of reference throughout the scv' eral views.

It is recognized that heretofore various forms of coupling devices have been provided which permit a relative advance movement of the tractor or leading vehicle in the event that drawn implement, or plow encounters a stone or other obstruction to its progress and that it is notbroadly new to employ this relative movement of the drawing and drawn vehicles to render the tractor inopc alive. However. the present construction is designed to immediately and entirely release the drawn implement or vehicle of the train. without. however. totally disconnecting it. but maintaining such engagement that the operated parts will be retained in alignment.

Referring to the drawings. l is the tractor or draft vehicle of which 2 is the carrying wheel, 3 the differential housing. -lthe st cering column and 5 the clutch control lever or pedal. Located to the rear of the tractor is the drawn implement or plow of which only the beam 6 is shown. lliter-connecting the plow beam 6 with the draft lug T ot the tractor is the releasable coupler forming the subject matter hereof. In constructing the coupler, there is employed a housing; 8 of substantially ovate form the outside being somewhat polygonal. This housing 8 is connected Willi the draft lug" 7 of the trac tor by a clevis 9, engaging about a transverse stud or pin 10 at one end of the llfillh ing 8, and transfixed by a coupling pin ll. which also extends through the draft lug 'i'. Mounted for riufiprocatory movement within the coupler housing 8, is a draft ha r or draw bar 152, having at its inner end an enlarged head 13, provided with oppositely disposed grooves or notches 14, extending parallel with the draw bar 19. The top and bottom of the housing 8 are provided with longitudinally disposed inwardly projccting ribs 15, shown particularly in Figs. 3 and l, which ribs engage within the notches or grooves 14, and afford guide ways for the draw bar to and from its operative or engaged position. The rear end of the. housing 8 is re-inforced at; 16 to form an abutment or shoulder stop for the draw bar head 13 at the limit of its retractive movement. The rear end of the draw bar 12 is bisected as at 17, or otherwise suitably tot-med for engagement with the plow beam 6, or with any other type of vehicle to be drawn. The form of connection or attachment of the coupler with the plow or other drawn implement and with the tractor, as by the clevis and coupling pin 11. are immaterial. It is obvious that other forms of connecting smegma means may be substituted. Located within the housing; 8 on opposite sides of the draw bar 12, are toggle pawls or jointed retaining arms. each comprising a svvingilrc arm portion 18. pivoted at it). upon studs mounted in the housing and movable thereabout to and from each other. For convenience of manufacture and assembly these arm portions 18 are preferably bifurcated at their oppositeends and are provided with intermediate web portions 18. Pivoted intermediate the furcations of the free ends of the swinging arms. 18 are the pawl heads or dogs 20. These heads or dogs are formed with oflset shoulder portions 21 for engagement with the ]"E112U'(l shoulder of the draw bar head 13. and provided with the extensions or finger like portions 22 extendin; on opposite sides of the draw bar head and having beveled or inclined Faces 23. intermediate the extensions or fingers 2'2 and the engaging: shoulders 21. Each dog or pawl head is provided with a tail portion it. which overhangs the intermediate web portion 18 of the swinging arm 19. and is provided with an adjusting screw 35 by which the relation or throw of the pawl head in one direction can be adjusted. luterposed between the swinging; arms lt-l and the adjacent sides of the [housing ti are helical tension springs 26, seating at their inner ends upon the intermediate web portions 18 ot the arm 18. which is provided with a projecting; stud 27 to form av seat for and center the sjin'ingz. At their outer ends the tension. springs 52G bear upon adjustable screw studs 28, screw threaded in the. side walls of the housing); 8, by the adjustment of which the tension of the spring may be varied at: will. its will be at once apparent. by an examination oi? Fig. 2, the engagement ot the draw arm 13 with the ot'lsct. shoulder 21 of the pawl heads or dogs .30 is slightly out of dead center relation with the pivotal portion of the pawl head and the swinging arm. The relative pull of the housing and the draw bar in opposite directions willthen tend to break or buckle the toggle, comprising the swinging; arm and the pawl head or dog. In this breaking or buckling movement of the toggle, the swinging arm l8 must necessarily move outward against the tension of its spring Qt). ll is to be understood that the pawl heads or dogs 20 are entirely tree for oscillatory movement about their pivotal connection with the arms ln Fig. 3 the position of the arm and pawl head at the extreme throw of the releasing movement is shown by dotted lines. itlincessive pull upon the 1 draw bar against; the engaging shoulders .21, tends to oscillate the dogs or pawl heads 2 which exert a lirrerage upon the arm 18 against the sprim moving the. arm outwardly until the head 13 of the draw bar the oppositely disposed engaging shoulders 21 of the respective toggle members. As the ivoted dogs or pawl heads approach releasing position the beveled or inclined faces 23 also engage the draw bar head asshown by dotted lines in Fig. 3, affording a fulcrum which materially assists in moving the stop shoulders 21 out of the path of the draw bar head, giving definition and a final accelerated movement to these stop shoulders. Thus the device will resist breakage or releasing influence, until the predetermined degree of resistance is exceeded, whereupon the release movement instead of being gradual and acoumulative will be effected comparatively quickly. thus giving instant relief to the obstructed drawn vehicle. With the stop may pass between shoulders 21 shifted out of the path of the draw bar head, the draw bar is free to move rearward within the housing through limited range of movement. In practice it is found that this movement need not exceed a. stroke of six inches, tions and relative movement of the parts may be modified and changed to meet various conditions of use. The fingerlike extensions 22 of the dogs or pawl heads, when in extreme operative position, approach closely to the guide ribs 15, upon the top and bottom of the housing 8, and serve to prevent accidental overthrow of the heads or dogs when the draw bar is released.

If it were not for these extensions 22, the pawl heads might occasionally be thrown to an abnormal position, wherein they would become interlocked with the guide ribs upon the reaction of the spring 26 and so intcrfere with or prevent the resetting of the parts. Upon the disengagement of the draw bar from the toggle arm, the springs 26 by their reaction will return the arms and their pawl head to the positions shown by solid lines in Fi 3, ready for reengagement of the draw bar head upon its retrograde movement. The draw bar 12 is never wholly disengaged or withdrawn from the housing 8. At the extreme limit of its reciprocatory movement the head 13 is arrested by rcenforcement stop'shouldcrs 16 of the housing. However, there will seldom or never belllltlt't or forcible engagement of 4 the draw bar head and the shoulders 16 for before the head has reached the limit. of its possible range of movement, the tractor will have been arrested by the disengagement of its driving clutch. To this end there is provided an intermei'liate connection between the tractor and the coupler comprising :1 cable 29 connected at 230 to the protruding portion of the draw bar 12 and extending thence preferably though not uia'cssarily, through an eye 31 in -the head of the coupling pin 11 and connected to :1V reciprocatory bar 32, having operative engagement with the clutch pedal movement.

at one end to the stu although the propor-.

or clip 37 is the bar 33 and engaging 5 of the tractor. In order to provide a take up device as before mentioned, the reciprocatory bar is formed in two sections, having relative longitudinal These may be merely two flat bars arranged side by side as shown in the sectional detail view Fig. 8. However, the preferable form is to provide a sleeve or channel 33, within which the primary bar 32 is mounted for reciprocation. In the construction shown in the drawings, the reciprocatory bar 32 is provided with a longitudinal slot 32 as shown by dotted lines in Fi 7, through which extends a stud or pin 34, carried by the channel bar 33, which while permitting relative longitudinal or telescopic movement of the bars 32 and 33 limits this movement to the length of the slot 32. ,A helical sring 35 is connected or pin 3d and at its opposite end, to a second pin 3% carried by the primary'bar 32, which spring tends to retract the bars 32 and 33, one toward the other. The forwardly extending end of the telescopic bar is pivotally connected to a .rock arm 36, mounted upon the clutch lover or pedal 5 for idle movement in one direction, but adapted when moved in the opposite direoti'on to carrycthe clutch pedal 5 with it. To this end a U-shaped bracket clamped about the clutch pedal arm 5 with the rock arm 36 pivoted between the ends of the U-shaped bracket or clip 37 upon the stud 3,8. A pin or stud 39 carried by the clip or bracket 37, extends 'into the path of movement of the lever 236 when moved rearwardly., This arrangement permits the clutch pedal 5 to be oscillated downwardly and forwardly thru its normal movement independent of the rock lever 2W, but in the event that the rock lever is oscillated by retraction of the telescopic bars 32-33, the clutch pedal is thereby operated through its operative; stroke. Thus in the normal operation of a tractor, the clutch pedal may be manipulated by the driver independent of and without interference with the coupler take up mechanism, but is under control of the coupler in the event that the coupler or interconnection is disengaged.

The telesco ic bars 32-33 are normally int'erconnecte one with the other by means of a locking lever or pawl 40, mounted upon a notch 1-1. in the reciprocatory bar 32. This locking lever or pawl 40 is actuated into and retained in locking relation by means of a spring l against the tension of which it. may he witlulrawu from the notch ll, by manual pressure of the handle or operating extension 4.4. For convenience the operating cable 29 has been shown as being guided over the top of the differential housing 3. Any other form of support or guide may be. utilized and if the clutclrpedal or other control member is lotake up bar.

gages. This point of contact of the draw bar head 13 with the dog being slightly out of dead center relation with the pivotal joints of the retaining arms, buckles or breaks these toggle arms against thetension of their respective springs 26. As the pawl heads or dogs turn under such pull of the respective implements or vehicles, the inclined faces 23 of the pawls or dogs 20 come in contact-with the draw bar head 13 to form fulcrums or hearing points facilitating the movement of the pawl heads to more quickly withdraw the stop shoulders 21, thereby causing the pawls or dogs to release the draw bar head quickly when once the releasing operation has been initiated. Bo-

: fore the draw bar and housing can relative- 1y move to the limits of their possible range of movement, wherein the head 13 would engage the stop shoulders lththe movement offtho tractor in relation with the plow or trailer implement will be sufiicient to tern sion the cable 29 to' draw the telescopic bars 32-33 rearwardly as the tractor continues toadvance, thereby oscillating the clutch pedal 5 to disengage the clutch and arrest the tractor. The tractor is thus brought to a.

stop beforevthe drew her head engages the stop shoulder 16, at the end of the housing, the draw bar still retaining its guiding relation with the ribs 15 of the coupler lions ing 8. The tractor thus having been automatically stopped cannot be again started nor hacked to permit reengagement of the coupler until, the clutch pedal 5 is released to permit r'eengagement of the driving clutch. To release the clutch pedal the driver will depress the handle or lover of the detent or looking pawl 40 of the take up de vice, thereby withdrawing the nose of the nawlfrom the notch 41.

The clutch-pedal 5 or control levers at the tractor are provided with retracting" springs which return the clutch pedal after each operation. Upon the disengagement ol the telescopic bars 32-33 bv the release of the pawl 40-from the notch 41. this clutch pedal spring, which is not shown on the drawing,

but which is a part of every tractor mechanism will by its reaction return the clutch edal to its normal position, advancing with it the bar 33 carrying the engaging pawl 40. In this movement the spring 35 is extended ceramic and placed under tension. It will be understood that the clutch pedal spring is of greater'strength than the spring 35. The clutch pedal having thus been released and the driving clutch reengaged the tractor is backed under power to slide the coupler housing 8 rearwardly upon the draw bar 12 until the head 13 between and beyond the engaging dogs 20 of the toggle arms, during which movement the take up spring 35 will have retracted thesliding bar 32 and cable 29 until the notch 41 again comes oppositc the locking pawl 40, which drops thereinto, thus resetting the parts preparatory to the HBXtOPBIHtIOIL' While the telescopic take up bar preferably comprisesa bar 32 reciprocating within the channel bar 33, as shown in detail in Fig. 7, these members may comprise two flat bars 32 and 33 arranged side by side as shown in Fig. 8, or the reciprocator bar may be enclosed within the fiat tu as shown at 32 and 33 in Fig; 9.

From the above description it will be'apparent that there is thus provided a device of the character described possessing the particular: features of advantage before enumerated as desirable, but which obviously is susceptible ol modification in its form, proportions, detail construction and arrange incnt of parts without departing form the principle involved. or szazrificing any of its advantages. j

While in order to comply with the stat etc the invention has been described in language more'or less specific as to structural features, it is to be understood that the inveution is. not limited to the specific details shown, but that the means and construction herein disclosed comprises the preferred form of several modes of putting the invention. into silent and the invention is there lore claimed in any of its forms or modifications within the legitimate and valid scope of the appended claims. 7

Having thus described my invention, I

claim:

' 1. In a releasing; coupler, of the character described, two telescopic members to be con-' nected with leading: and trailing vehicles respectively, a pair of toggle pawl arms arranged, in opposite relation upon one of the telescopic members and engaging the other member, springs against the tension. of which the opposite aawl arms yield to release the engaged mom er under predetermined pulliii-g influence, means for limiting the 'tele scopic movement of the members whereby they will be maintained in engagement one with the other. and guidingmeans by which the members are guided-during retrograde adjustment to their engaging relation.

2. As an article of i'nanu'lacture, an automatic stop device for a tractor vehicle having a movable control member,-to which tractor a drawn vehicle is connected by a releasable hitch, upon the disengagement of which the stop device becomes operative, comprising a pair of relatively adjustable bars, one of the bars being connected to the draft vehicle control member and the other bar being connected to the drawnvehicle, and a detent delachablv interconnecting the bars one with the other, whereby the relative movement of the draft and drawn vehicles upon release of the coupling will exert a pulling strain upon the interconnected bars to effect the operation of the draft vehicle control member, the detent being releasable, and the bars being capable of relative movement upon release of the detent. and said control member being capable of return movement upon the relative movement of the bars, said control member upon restoration enabling the return of the draft and drawn vehicles to coupled re lation. said bars being returnt-zd to the control of the detent. upon the re-coupling of the vehicles.

3. As an article of manutactm'e, an automatic stop device for a tractor vehicle having a movable control member, to which tractor a drawn vehicle is connected by a releasable hitch, upon the. disengagement of which the stop device becomes operative, comprising a trip connection between the drawn vehicle and the movable control member of the draft vehicle operable upon relative movement of the drawn and draft vehicles after detachment of their coupling to actuate the control member, a releasable detent for said trip connection, said control member being released for return movement by the release of the trip connection detent, and means for eliecting, the reengagement of the detent with the trip connection upon the return of the draft and drawn vehicles to coupled relation.

4. As an article of manufacture, an automatic stop device for a tractor vehicle having a movable control member, to which tractor a drawn vehicle is connected by a releasable hitch, upon the disengagement of which the stop device becomes operative, comprised of an extensibleand contractible trip connection operatively connecting the control member of the draft vehicle with the drawn vehicle, said trip connection being actuated by relative movement of said vehicles, the control member being automatically operated by the actuation of the trip connection, means normally resisting the extension of said trip connection during its operation of said control member and thereafter operable to permit the extension of said trip connection to enable the return of the control member, said connection being automatically contractible to normal resistant condition upon the recoupling of the draft and drawn vehicles.

5. In an extensible coupling of the character described, a draw bar having oppositely disposed engaging shoulders, pivoted jointed arms arranged on opposite sides of the draw bar and engaging said shoulders with equalized pressure in relation slightly ottset from dead center relation with the pivotal joints of the respective arms, and tension springs for said arms against the influence of which said arms yield to release the draw bar when subjected to abnormal pulling efi'ort, the equalized pressure of the yielding arms on opposite sides of the draw bar serving to guide the draw bar during its retrograde movement with minimum resistance to such movement to re-engaging position.

6. In a releasable tractor hitch construction, the combination with an automatically extensible coupling between the tractor and a trailing vehicle, of a connection to the motive control mechanism of the tractor operated by the extension of said couplin to arrest the progress of the tractor, inclu ing a reciprocatory telescopic bar, a manually releasable detent normally interconnecting the members of the telescopic bar and a retracting spring for the bars tending to move the bars to position to be interconnected by said detent, one of said bars being connected with the motive control mechanism of the tractor, the other member being movable by the relative movement of the tractor and trailing vehicle and transmitting movement through the inter-engaging detent to the first member to actuate the motive control mechanism of the tractor.

7 A releasable tractor hitch of the character described wherein a tractor and a trail-;

ingvehicle are interconnected by acoupler releasable under influence of abnormal pulling effort characterized by a separable connection between the trailing vehicle and the motive control mechanism of the tractor,

means for detachably connecting the sepa-.

actuating connection for the motive control mechanism of the tractor operated by the relative movement of the tractor and f railing vehicle upon yielding of the coupler, an automatic take up device in said actuating connection, and means for positively locking said take up device against operation during normal operation of the tractor and trailing vehicle, said take up means being effective during retrograde movement of the tractor after operation of the coupler for resetting the actuating connection.

9. A tractor hitch wherein a tractor and a trailing vehicle are interconnected by a coupler adapted to yield under influence of abnormal pulling eliort, characterized by a spring tensioned motive power control member for the tractor, an actuating connection for the power control member operated by the relative movement of the tractor and trailing vehicle upon the yielding of said coupler, to move the power control member against the tension of its spring, a releasable coupler in said actuating connection permitting the return of the power control memher under the influence of its tension spring and a retracting spring for the actuating connection tensioned by the return of said power control member to return the connection to operative condition upon retrograde movement of the tractor.

10. A draft connection of the class scribed, including a drawn member, a trac tor member having a control element, a yielding coupling connecting the tractor and drawn member, two telescopic members, operntirely connected with the tractor control element and operative in unison upon the yielding of the coupling to operate the control clement, interconnecting means normally connecting the telescopic members for unison operation, said interconnecting means being releasable to permit the telescopic members to compensate for return operation of the control element and the retraction of the vehicles to their normally coupled relation.

In testimony whereof, I have hereunto set my hand this 20th day of September A. l). 1922.

VERNON H. LAMBERT. 

